JTreeReader.hh

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#ifndef __JROOT__JTREEREADER__
#define __JROOT__JTREEREADER__

#include "TFile.h"
#include "TTree.h"
#include "TDictionary.h"

#include "JROOT/JRootAddress.hh"
#include "JROOT/JTreeParameters.hh"
#include "JLang/JPointer.hh"


/**
 * \file
 * TTree reading for template data type.
 * \author mdejong
 */
namespace JROOT {}
namespace JPP { using namespace JROOT; }

namespace JROOT {

  using JLANG::JPointer;
  

  /**
   * Interface for TTree reading.
   */
  struct JAbstractTreeReader : 
    public JPointer<TTree>
  {
    /**
     * Load TTree from given file.
     *
     * \param  file          pointer to file
     * \return               true when TTree correctly loaded; else false
     */
    virtual bool load(TFile* file) = 0;


    /**
     * Get ROOT dictionary.
     *
     * \return               dictionary.
     */
    virtual const TDictionary* getDictionary() = 0;
  };


  /**
   * Auxiliary class for template TTree reading.
   */
  template<class T>
  class JTreeReader : 
    public JAbstractTreeReader,
    public JTreeParameters,
    public JRootAddress<T>
  {
  public:
    /**
     * Constructor.
     *
     * Note that the default TTree parameters are obtained using method JROOT::getTreeParameters.
     *
     * \param  parameters    parameters of TTree
     */
    JTreeReader(const JTreeParameters& parameters = JROOT::getTreeParameters<T>()) :
      JTreeParameters(parameters)
    {}


    /**
     * Load TTree from given file.
     *
     * This methods releases the pending memory allocated from previous data reading.
     *
     * \param  file          pointer to file
     * \return               true when TTree correctly loaded; else false
     */
    virtual bool load(TFile* file) override 
    {
      this->release();

      if (file != NULL) {

        this->set(dynamic_cast<TTree*>(file->Get(this->getTreeName())));
      
        if (this->is_valid()) {

          this->get()->SetBranchAddress(this->getBranchName(), &this->address);

          return true;
        }
      }

      return false;
    }


    /**
     * Get ROOT dictionary.
     *
     * \return               dictionary.
     */
    virtual const TDictionary* getDictionary() override 
    {
      return TDictionary::GetDictionary(T::Class_Name());
    }
  };
}

#endif